Corrections to the Fermi Matrix Element for Superallowed<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>β</mml:mi></mml:math>Decay

Abstract

Corrections to the Fermi matrix element for superallowed transitions due to isospin nonconservation are reexamined. The sources of theoretical uncertainty and the possibility of a previously neglected correction based on the mismatch between the spectator nucleons are investigated. The consequences to the conserved-vector-current hypothesis and the Kobayashi-Maskawa mixing angles are discussed.